Abstract
The fertility restorer gene, Rf1, encodes a PPR protein involved in pollen formation in BT-type cytoplasmic male sterility (BT-CMS) rice. Rf1 promotes the processing of co-transcribed atp6-orf79 transcripts in mitochondria resulting in reduction of accumulation of ORF79 protein and restoration of fertility. However, a question how the Rf1 protein inhibits the expression of orf79 is still opened. We here show that the processing invoke the degradation of orf79 transcripts. In the restorer line, processed atp6 transcripts were associated with polysome, but the processed orf79 transcripts were not. Unprocessed atp6-orf79 transcripts in sterile line were found in polysome fraction, suggesting the expression of ORF79 protein is abolished at the level of RNA stability and translation. We also present a function of Rf1 for another type CMS in rice.
